This invention relates to an imaging arrangement. It is well known to produce two-dimensional images of a viewed scene, for example by means of a television camera or the like. Conventional viewing systems of this kind tend to be restricted as to the optical bandwidth to which they are sensitive, and in particular they are generally insensitive to infrared (thermal) radiation. Various kinds of thermal imaging systems are well known, and include specially adapted television-like cameras having a shutter in front of a heat sensitive image surface which responds to the changes in temperature, resulting from shutter action. An alternative kind of thermal imaging system of higher resolution involves the use of a scanning arrangement which causes each part of a scene to be viewed in turn by a small very sensitive sensor or array of sensors. It is, however, difficult to correlate such a thermal image of a scene with its optical equivalent, in which the optical images result from light reflected by the viewed scene. Such correlation can be important if it is desired to extract data relating to various characteristics of an object in the viewed scene so as to identify it or determine the nature of its movement.
The present invention seeks to provide an improved imaging arrangement.